docs: def _collection_names_result(self, callback, results, error=None):
          """callback to for collection names query, filters out collection names"""
          names = [r['name'] for r in results if r['name'].count('.') == 1]
          assert error == None, repr(error)
          strip = len(self._pool._dbname) + 1
          callback([name[strip:] for name in names])